Traffic snags on Juniper router glitch

'Interface flapping'

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Juniper has published a security update designed to fix a bug involving its router software.

The glitch in JUNOS creates problems for networking kit from Juniper in processing Border Gateway Protocol (BGP) traffic. BGP is a core routing protocol of the internet that's widely used by ISPs and others to (put simply) map the best available routes for traffic to flow across the internet.

Left unfixed the flaw means that malformed BGP packets may induce "interface flapping".

Interface flapping means the interface of a network device is left going up and down repeatedly - like a tart's knickers, though on a much accelerated scale. The behaviour, on a large computer network, might be used to exhaust the memory buffers on devices targeted with malformed IPv6 messages. This, in turn, might lead to lost datagrams and general network chaos.

JUNOS releases from 7.3 to 8.4 are potentially vulnerable. Users are urged to upgrade their software to 8.5R1. The bug lends itself to remote exploitation, making it possible that it might form the basis of denial of service attack by hackers against service providers running Juniper kit.

Juniper is a strong number two behind Cisco in the supply of routing kit to large ISPs and telcos. One or two telco techies are already reporting minor glitches that they blame on the problem. A discussion on the issue can be found here. ®